Electrical radiant panel heater



Oct. 13, 1964 A. GoLDs'rI-:IN 3,153,138

ELECTRICAL RADIANT PANEL HEATER Filed June 14. 1962 2 sheets-sheet 1 Oct. 13, 1964 A. GQLDSTEAN 3,153,138

ELECTRICAL RADIANT PANEL. HEATER Filed June 14. 1962 2 sheets-sheet 2 United States Patent O 3,153,13s ELECTRICAL RADIANT PANEL HEATER Arthur Goldstein, 375 Milton Road, Cambridge, England Filed June 14, 1962, Ser. No. 262,523

` 3 Claims. (Cl. 219-342) This invention relates to electric heaters and particularly low-temperature-radiation electric heaters, and has for its object to provide such devices of light weight and high efficiency, which operate without oil or any other liquid with its attendant disadvantages, and which are readily manufactured.

An electric heater according to the present invention comprises a front plate of light gauge metal sheet, prefer-ably mild steel, which is formed on its inside surface with recessed grooves extending horizontally and vertically to a desired pattern over its area, to receive a continuous relectric heating Wire or element covered with a suitable electrically insulating and heat-resisting material'or materials.

A back plate, of light gauge metal sheet, is also provided which has the width of but is less in height than the front plate and which is located to the rear of the front plate in contact with its inside surface. This back plate is spot welded to the front plate preferably in a plurality of positions more or less uniformly disposed over the whole area. 1

With the back plate welded in position, the covered electric heating wire is threaded through a desired pattern of the grooving so that it is more or less uniformly disposed over the whole area of the plates, and the ends are brought to a desired position, for example at the rear of the back plate, and then connected to an insulating terminal block having connected thereto a suitable ilexible lead terminating in a pin or other plug. The outer edges of the front and back plates are held together by abeading of suitable section.

' Electric heaters in accordance with lthe present invention have the back plate extending laterally to the edges of the front plate, but at the top and bottom stopping short, except for the corners, of upper and lower horizontal grooves in which horizontal portions ofthe heating wire which connect the vertical portions, are located, and the exposed portions of the rear surface of the front plate lying between the upper and lower edges yof theback plate and the beading are covered over by removable horizontal stripfpanels of suitable section, the ends of which panels are sprung into and accommodated in iiattened sheet metal sockets having anges spot welded to the backfplate at and adjacent the extending corner portions thereof.

In accordance with a further feature of the present invention, the beading portions are secured in position by spot welding.

In order that the invention may be better understood, it will now be described with reference to the accompanying diagrammatic drawings which are given by way of example only and in which: y

FIG. l is a rear elevation of an assembled part of one embodiment of a heater in accordance with the invention.

FIG. 2 is an enlarged fragmentary perspective View yof a detail of FIG. l.

FIGS. 3 and 4 are elevations of removable strip panels for mounting in position on the assembly shown in FIG. l. i

FIGS. 5 and 6 are enlarged sectional elevations of the panels shown in FIGS. 3 and 4 respectively.

FIG. 7 is a front'elevation, to an enlarged scale, of upper and lower corner portionsofthe assembly'shown in FIG. 1.

FIG. Sis a rear elevationto the scale of FIG. 7, of

ice

the upper and lower corner portions, showing the ends of the strip panels in position.

FIG. 9 is a sectional side elevation of FIG. 7. Y

lFIG. 10 is an elevation to a large scale of a portion of a covered heating wire it is preferred to employ, with the covering partly unravelled and partlyin section to illustrate the method of fabrication.

FIG. l1 is a front elevation of the complete heater, an assembled portion of which is shown in FIG. l, and

FIG. 12 is a side elevation of FIG. 1l.

In the drawings, 1G is the back plate which has the same width as the grooved front plate 11. At the side portions it has upwardly and downwardly projecting corners 12, 13, 14 and 1S, giving these side portions, at the sides only, the same height as the front plate 11. Between the corner portions 12 and 13 there is a cutaway portion giving to the backy plate an upper edge 16, and between the corners 14 and 15 there is a cut-away portion giving to the back plate a lower edge 17.

These edges 16 and 17 are so disposed that when the parts are assembled, as shown in FIG. 1, the upper edge 16 comes justbelow the uper horizontal groove 18 in the front plate, and the lower edge 17 cornes just above the groove 19 in the front plate, as shown in FiG. 1. When the welded-together frontend back plates are bound by the headings 2G and 21, the sides and the corner portions of the two plates come within the headings. Gnly the front plate, however, comes within the beading in the portions extending between the corners 12 and 13, and 14 andlS. However, the headings are spot welded in position, for example in the positions indicated by the markings 22, and it will be realised that this leaves gaps between the upper and lower edges of the back plateiand the headings, toV enable the heating wire shown diagrammatically by the thickened line 23, FIG. l, to be threaded in position.

The corner portions 12, 13, 14 and 15 of the back plate have welded thereto flanged iiattened sockets 24 in the manner shown in FIG. 2. These face yeach other in pairs, and the upper pair can have sprung thereinto the strip panel 25 to close the upper gap, and the strip panel 26 to close the lower gap.

As indicated at 27, FIG. 4, the panel 26 has an aperture to acconnnodatev the casing for the switchy and telltale light. j

The section FIG. 9 shows the upper panel strip 25 removed to illustrate how the heating wire 23y can be put into position. The lower part of FIG. 9 shows the panel 26 in position but also indicates by a dot and dash line the method of threading the wire 28. As shown in the drawings, the `pamels 25 and Ztiare generally ofkiiat formation but have a slight channel section. f

When the welded-together unit shown in FIG. l (with` the exception of the wire 23) has been fabricated,` it is possible for the said unit to be vitreously enamelled and then subsequently wired; the separate panels 2S and26` i from fine glass ibers and this inner covering is impreg-r nated with silicone varnish. After this an outer cover- `ing32 is applied; this also is yof yarns 33 made up yfrom iine glass libres and this outer covering is'tinished by being impregnated with silicone varnish.

When dry, the silicone-vainish-treated glass fibre covering not vonly acts as an adequate 'electrical insulating .materiah .but it is also highly resistant to heat, especially the low heat, say 199 F.,'which in use theheater attains..

The complete structure of the embodiment of the heater partly shown in FIGS. 1 to 8, is shown in FIGS. ll and '12. In these figures, lll is the rectangular front plate with rounded corners which has a pattern of grooves, prising an uppermost 1S, another 19 adjacent the lowermost 34, and three 35 in intermediate positions, as well as twenty vertical grooves uniformly spaced apart. Of these latter, the outermost 36 and 37 are adjacent the shorter edges of the assembled plates and extend between the ends of the uppermost and lowerniost horizontal grooves I8 and 19 respectively. The other vertical grooves 38 in the intermediate positions extend between the uppermost horizontal grooves l and 19. Thus, on the outside surface, the projections due to the grooves bound a plurality of sunken plane rectangles 39.

- The back plate is spot welded to the front plate 11, in a plurality of positions, for example at the points 40 which are disposed at the centre of the sunken plane rectangles 39 of the front plate. The covered heating wire indicated by the dotted line 23 is shown in position.

41 indicates a tell-tale lamp which may be included in the construction and which is connected to a branch or parallel circuit, to indicate at the front if the heater is on" or off This circuit is in a terminal block 44 of insulating material located to the rear of the lower left-hand side of FIG. 11, which is covered in by a detachable casing 45 through which the lead to the exterior passes.

The structure thus formed can be carried by any suitable means, to stand on a oor or to be suspended on a wall. For this purpose, and as shown in FIGS. ll and 12, lit has two tubular metal uprights 42 secured by screws towards the side edges at the rear, the lower ends of which are supported in feet 43 formed from hollow rectangular castings. When turned one way, and as shown, the feet allow the plane of the heater to be spaced from a wall and, when turned the other way, to come closer to the wall.

It will be realised that after preliminary use (such preliminary use possibly extending over some years) it will be a simple matter, if necessary, to obtain access to the heating wire for any required purpose, by merely removing the panels and Z6. After replacement or repair, the panels can be sprung back into position for a further period of use.

What I claim is:

1. A low-temperature-radiation electric heater comprising a front plate formed from a rectangular sheet of metal of light gauge having extending'over the major part of the area of one surface thereof a plurality of horizontally spaced vertical grooves, crossed by a plurality of vertically spaced horizontal grooves, the upper and lowermost horizontal grooves intersecting the ends of the vertical grooves, together with a back plate formed from a generally rectangular sheet of metal of light gauge having the same width as the front plate and the same height as said front plate at the side edges and four side portions of small width bounded by said side edges, said vertical and horizontal grooves forming channelways between said front and back plates, the two plates being spot welded together so that their side edges throughout their lengths are in coincidence, the upper and lower portions of the back plate being cut out to forrn access openings between the side edge portions with their upper and lower edges spaced from the upper and lower edges of the front plate, to leave four projecting corner portions on said back plate and to provide uncovered upper and lower rear portions of the front plate in registry with the upper and lower grooves of the front plate and to permit installation of an electric heating element in said channelways, a channel section continuous beading arranged around the bounding edges of the front and back plates and secured to these parts by spot welding, a removable continuous electric heating element covered with an electrically insulating and heat-resist ing material threaded in the channelways through said access openings of the back plate, a terminal block of insulating material secured to the front plate to which the ends of the electric heating wire are secured and having an exterior lead therefrom, a shaped sheet metal socket spot welded to each of the two upper corner portions of the back plate located at the ends of said cut out portions with the socket openings facing'one towards the other, an upper elongated rectangular resiliently flexible sheet metal panel having a width to cover the exposed upper rear part of the front plate including the upper horizontal groove and being of a length so that the two ends project beyond the ends of said exposed part and to enable said panel to be sprung into said sockets, a shaped sheet metal socket spot welded to eachtof the two lower corner portions of the back plate located at the ends of said cut out portions with the socket openings facing one towards the other, and a lower elongated resiliently flexible rectangular sheet metal panel having a width to cover the exposed lower rear part of the front plate including the lower horizontal groove and a length so that the two ends project beyond the ends of said exposed part to enable said panel to be sprung into said last named sockets.

2. A low `temperature-radiation electric heater as set forth in claim 1, in which said front and back plates, said beading, and said sockets for said flexible sheet metal panels are vitreously enamelled.

3. In a low temperature-radiation electric heater, comprising front and back plates each formed from a rectangular sheet of light gauge metal in which one of said plates is provided with spaced horizontal grooves extending in parallel relation and a plurality of vertical grooves intersecting said horizontal grooves and arranged in parallel spaced relation, said plates being spot welded together with their side edges throughout their lengths arranged in coincidence, said grooves forming electric heating element receiving channelways between the front and back plates, the other or" said plates being provided with longitudinally extending cut out portions adjacent the edges thereof to forni access openings for said heating element receiving channelways, said cut out openings being formed to register with substantially the entire lengths of said horizontal channelways along opposed edges of said front and back plates, bracket plates at the ends of each said cut out portions each having a recess with the recesses of said bracket plates arranged in opposed relation, a removable continuous electric heating element having a covering of electrictinsulating and heat resisting material threaded through the channelways between the front and back plates through said cut out portions, and a flexible removable cover strip for closing each of side access openings, said strip being flexible and sprung into position with its ends received in said opposed sockets.

References Cited in the tile of this patent UNITED STATES PATENTS 2,354,224 Stein July 25, 1944 2,526,606 Gregg Oct. 17, 1950 FOREIGN PATENTS 779,520 Great Britain July 24, 1957 

3. IN A LOW TEMPERATURE-RADIATION ELECTRIC HEATER, COMPRISING FRONT AND BACK PLATES EACH FORMED FROM A RECTANGULAR SHEET OF LIGHT GAUGE METAL IN WHICH ONE OF SAID PLATES IS PROVIDED WITH SPACED HORIZONTAL GROOVES EXTENDING IN PARALLEL RELATION AND A PLURALITY OF VERTICAL GROOVES INTERSECTING SAID HORIZONTAL GROOVES AND ARRANGED IN PARALLEL SPACED RELATION, SAID PLATE BEING SPOT WELDED TOGETHER WITH THEIR SIDE EDGES THROUGHOUT THEIR LENGTHS ARRANGED IN COINCIDENCE, SAID GROOVES FORMING ELECTRIC HEATING ELEMENT RECEIVING CHANNELWAYS BETWEEN THE FRONT AND BACK PLATES, THE OTHER OF SAID PLATES BEING PROVIDED WITH LONGITUDINALLY EXTENDING CUT OUT PORTIONS ADJACENT THE EDGES THEREOF TO FORM ACCESS OPENINGS FOR SAID HEATINGS BEING FORMED TO REGISTER WITH SUBSTANTIALLY THE ENTIRE LENGTHS OF SAID HORIZONTAL CHANNELWAYS ALONG OPPOSED EDGES OF SAID FRONT AND BACK PLATES, BRACKET PLATES AT THE ENDS OF EACH SAID CUT OUT PORTIONS EACH HAVING A RECESS WITH THE RECESSES OF SAID BRACKET PLATES ARRANGED IN OPPOSED RELATION, A REMOVABLE CONTINUOUS ELECTRIC HEATING ELEMENT HAVING A COVERING OF ELECTRIC INSULATING AND HEAT RESISTING MATERIAL THREADED THROUGH THE CHANNELWAYS BETWEEN THE FRONT AND BACK PLATES THROUGH SAID CUT OUT PORTIONS, AND A FLEXIBLE REMOVABLE COVER STRIP FOR CLOSING EACH OF SIDE ACCESS OPENINGS, SAID STRIP BEING FLEXIBLE AND SPRUNG INTO POSITION WITH ITS ENDS RECEIVED IN SAID OPPOSED SOCKETS. 